1. Field of the Invention
This invention relates to sewing machines in general and more particularly to sewing machines having preprogrammed stitch patterns and electronic means for selectively controlling the stitch forming instrumentalities to produce a selected stitch pattern.
2. Description of the Prior Art
It will be appreciated by one skilled in the art of sewing that it is advantageous to limit the maximum sewing speed during the formation of certain intricate stitches to minimize the possibility of poorly formed stitches. Some prior known electronic sewing machines have heretofore stored motor speed information with pattern information in an electronic memory. Such machines have required additional complex electronic components to decode the motor speed information and use it to limit the speed of the sewing machine motor.
One problem associated with some prior known sewing machines having electronically controlled stitch forming instrumentalities is that they did not automatically limit the maximum motor speed during the formation of certain stitches and were thus subject to improper stitch formation.
Another problem is that sewing machines which stored speed information in an electronic memory required complex electronic circuits to decode the information and control the sewing machine drive motor.
Another problem is that the operator was required to remember which stitches should not be sewn at the maximum motor speed on sewing machines in which the speed information was not stored in an electronic memory.
Still another problem is that an operator could accidentally depress the foot controller and operate the sewing machine at a higher-than-desirable motor speed while sewing intricate stitches.